Monday, the first day of trading since the announcement that Saudi Arabia had agreed to buy a hundred and ten billion dollars in U.S. weaponry, defense stocks jumped.

“General Dynamics (GD.N), Raytheon (RTN.N), and Lockheed Martin (LMT.N) all hit record highs before easing to trade up between 0.4 percent and 1.6 percent,” Reuters reported. “Boeing (BA.N) was up 1.3 percent and the second-biggest boost to the Dow.”

In Donald Trump’s world, that counts as another win. “Tremendous day,” the President said on Saturday, when the arms deal was first made public, “hundreds of billions of dollars of investments into the United States and jobs, jobs, jobs. So I would like to thank all of the people of Saudi Arabia.”

Of course, the “people” of the desert kingdom didn’t have anything to do with making the deal. It was done by the ruling House of Saud, which has had intimate ties to the Pentagon, U.S. intelligence agencies, and American defense companies since 1943, when Franklin Delano Roosevelt declared, “The defense of Saudi Arabia is vital to the defense of the United States.” During the past seventy years, the Saudi monarchy has struck many, many arms deals with the U.S., including a $60.5 billion agreement with the Obama Administration, in 2010.

So what, if anything, is different this time?

First, the agreement marks another policy U-turn from Trump. During his election campaign, he described the Saudi government as “people that push gays off buildings,” and said they “kill women and treat women horribly.” Trump also suggested that Saudi Arabia was behind the terrorist attacks on 9/11. “Take at look at Saudi Arabia, open the documents,” he demanded. Instead of following up this declaration now that he is President, Trump has agreed to supply the Saudi defense forces with more U.S.-made tanks, planes, helicopters, ships, bombs, and other weapons systems.

The second notable aspect of the agreement is its scale. The Secretary of State, Rex Tillerson, wasn’t exaggerating when he described it as “huge.” As Tillerson explained, it covers five broad categories: air-force modernization; air and missile defense; border security and counterterrorism; maritime and coastal security; and communications and cybersecurity.

Third, and perhaps most perniciously, the deal means that the United States is stepping up its support for Saudi Arabia’s proxy war against Iranian-backed Houthi rebels in Yemen, the poorest country in the Middle East, in which more than ten thousand civilians have already been killed, an unknown number of whom were blown to pieces by American-supplied bombs. In a piece published at the Hill, Kristine Beckerle, a researcher at Human Rights Watch, said her organization had documented eighty-one attacks by the Saudi-led coalition in Yemen over the last two years, many of which were “possible war crimes. In almost two dozen of these cases . . . we were able to identify the U.S. weapons that were used.”

Tillerson, who is familiar with the Saudi government from his years as the chief executive of ExxonMobil, didn’t refer to any of this in his remarks on the deal, of course. Instead, he said that the arms sale was intended to help Riyadh counter the “malign Iranian influence and Iranian-related threats which exist on Saudi Arabia’s borders on all sides.” One of these threats, in the Saudis’ telling, is the Houthi rebel movement that seized Sanaa, the capital of Yemen, in 2015, forcing the Saudi-backed government of President Abdo Rabo Mansour Hadi to take refuge in the port city of Aden.

Yemen’s civil war is a complicated conflict, rooted partly in tribal rivalries and religious differences: the Hadi government and most of its supporters are Sunni muslims, while the Houthis are Shiites. A couple of things are clear enough, though. The support that Saudi Arabia and Iran have supplied to their respective proxies has only intensified the conflict. And conditions on the ground are getting worse. Because the Saudi coalition has destroyed key bridges, airfields, and ports, many Houthi-controlled areas are running desperately short of food and medical supplies. ”With almost 19 million reliant on aid, #Yemen is the world’s single largest humanitarian crisis,” the International Committee of the Red Cross said in a tweet a few days ago. “Now it’s in the grip of a cholera outbreak.”

Members of the Obama Administration must bear some of the responsibility for allowing the Saudis and their allies to hit civilian targets with U.S.-supplied bombs, but they did eventually impose some restrictions. Last May, after issuing repeated verbal warnings that went mostly unheeded, the Administration suspended sales to Riyadh of cluster munitions, which release dozens of small bombs over a wide area. In December, after the Saudi coalition bombed a funeral in Sanaa, killing about a hundred and forty people, the Obama Administration announced that it would no longer allow the Saudis to buy some precision-guided heavy bombs. Trump has now reversed this policy, agreeing to supply the Saudis with the very types of weapons they used in the deadly attack on the funeral. “Lifting the suspension on precision-guided munitions is a big deal,” William Hartung, the director of the Arms and Security Project at the Center for International Policy, told Mother Jones. “It’s a huge impact if it reinforces the Saudi bombing campaign in Yemen, and also the signal that it’s okay with us. It’s saying, ‘Have at it. Do what you want.’ ”The Saudi-sponsored spread of Wahhabism, a fundamentalist brand of Islam, surely demonstrated that what the House of Saud wants isn’t necessarily good for the United States and other Western countries. In Yemen, the problem isn’t fundamentalist Saudi preachers; it is Saudi pilots dropping American-made bombs. An obvious concern is that, as a result of this deal, terrorist groups will find more recruits eager to strike the West.

“As we speak, millions of Yemenis are being radicalized against the country they blame for the civilian deaths,” Senator Chris Murphy, the Democrat from Connecticut, pointed out in a piece at the Huffington Post. A bill that Murphy has co-sponsored with Senator Rand Paul, the Kentucky Republican, would restore some limits on the sorts of weaponry that can be sold to Saudi Arabia, but it seems very unlikely to become law. “By selling the Saudis these precision-guided weapons more—not fewer—civilians will be killed because it is Saudi Arabia’s strategy to starve Yemenis to death to increase their own leverage at the negotiating table,” Murphy went on in his piece. “They couldn’t do this without the weapons we are selling them.”

Trump and his colleagues are too busy boasting about, and exaggerating, the economic benefits of the new arms agreement to pause and consider its broader implications. But, as President Dwight D. Eisenhower warned more than half a century ago, what’s good for the military-industrial complex isn’t necessarily good for America, or the world.